Resulting Schechter parameters L^* and α from a non-linear least-squares fit (using the Levenberg-Marquardt algorithm) of the Schechter function (Eq. (19)) to the binned differential 1/V_max estimator (Eq. (8)) for different binning schemes. Panels from left to right show five different bin sizes Δ log L_Lyα[erg s⁻¹] = {0.075, 0.1, 0.15, 0.2, 0.25}. Colour-coded in each panel is the best-fit (L^*, α) pair according to the lowest-luminosity boundary of the starting bin. Incomplete bins (containing objects at f_c <  0.15) are ignored in the fit, i.e. the magenta point in the panel Δ log L_Lyα[erg s⁻¹] = 0.2 panel represents the adopted binning scheme (see Sect. 4.2) in Table 2 and Fig. 17. For guidance the likelihood contours and the maximum-likelihood solution from Fig. 12 are shown in each panel.